Bonjour
Une idée (un peu tordue ?)
Juste ces 2 procédures dans le code de l'userform
Private Sub TextBox1_Change()
Me.TextBox3.Text = Replace(Format(Val(Replace(Me.TextBox1, ",", ".")) + Val(Replace(Me.TextBox2, ",", ".")), "#,##0.00"), Chr(160), ".")
End Sub
Private Sub TextBox2_Change()
Me.TextBox3.Text = Replace(Format(Val(Replace(Me.TextBox1, ",", ".")) + Val(Replace(Me.TextBox2, ",", ".")), "#,##0.00"), Chr(160), ".")
End Sub